Sony Walkman NWZ-A801 Replacement Battery 3.7V 650mAh

Sony NWZ-A801 / NW-A805 Series — 3.7V Li-Polymer Replacement Battery (LIS1374HNPA)

This is a 3.7V 650mAh Li-Polymer battery for the Sony Walkman NWZ-A801, NW-A805, NW-A805B, NW-A805P, and compatible models. It replaces OEM part numbers LIS1374HNPA, 1-756-702-11, and 7607A12353. Swap it in when the original cell can no longer hold charge or the player stops powering on.

• NWZ-A801 and NW-A805 compatibility: These models share the same battery bay dimensions, connector orientation, and voltage rail. The 3.7V nominal output matches the original cell, so the player's fuel gauge reads correctly from the first charge cycle.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the NW-A805 platform. The BMS accepted full charge current without triggering protection cutoff, and the player's on-screen indicator tracked state-of-charge without jumping.
• First-charge protocol for NWZ-A series players: After installing, connect the charger before attempting to power the device on. These players enter a deep-discharge protection state during storage that requires slow trickle current before normal charge current is accepted. Skipping this step causes the player to sit at a blank screen with no charge indication.

Battery percentage jumping after cell swap on NWZ-A801

The NWZ-A801 uses a voltage-threshold method to estimate remaining charge. After a cell swap, the player has no charge history for the new cell and maps voltage readings against old reference points. This causes the percentage indicator to jump — sometimes skipping 20–30% in a single session. Run two full charge-to-discharge cycles and the indicator stabilises as the player builds a new voltage profile for the replacement cell.

Playback cutting out before the battery indicator shows empty

The audio amplifier in these compact players draws a brief current spike when driving headphone output at higher volumes. Near the end of discharge, a weakened or aged cell cannot sustain that spike without its voltage dipping below the BMS cutoff threshold. The player shuts down even though the gauge still shows a bar or two remaining. A fresh cell with full capacity handles the spike without voltage sag — install the replacement and the cutoff moves back to where the gauge actually reads near zero.